Wired and Wireless Networks Finished Flashcards
What is a network
Two or more computers connected together with the purpose of communication
How can networks be connected (2)
Wired media such as cables
Wireless media such as WiFi
What is a computer or device that isn’t connected to a network called
A stand-alone
What are the advantages of using networks (8)
File sharing Hardware sharing Communication Roaming access Centralised maintenance and updates Centralised security User monitoring Levels of access
What are the disadvantages of networks (4)
Cost
Requires trained management
Spread of malware
Hacking
What does LAN stand for
Local area network
What does WAN stand for
Wide area network
What is a LAN
A network that is geographically confined to one building or site
Where are LANs commonly used (3)
Small businesses/organisations
Schools
Homes
What is a WAN
A network spread over a wide geographical area
Where are WANs commonly used
Organisations that have more than one office or branch
One example of a WAN
The internet
What are the different models for connecting computers over a network (2)
Client-server networks
Peer-to-peer networks
What is a server in a client-server network
A computer that manages and stores files
What are the different types of servers and what do they do (5)
File servers - hold and maintain user files
Applications servers - allow programs to be run over a network
Web servers - hold and share web pages
Print servers - manage printing across a network
Mail servers - handle emails between users
What is a client
A computer that relies on servers to provide and manage data
What is the function of a peer-to-peer (P2P) network
Each computer in a status has equal control over the network
What does a computer need to connect to a network (3)
Network interface controller (NIC) or wireless NIC
Wired or wireless transmission medium
A point to connect to such as a router, hub, switch or wireless access point
What does a NIC do
Provides a method of connecting to a network
What does a NIC provide (2)
An interface port for a wired connection or
A radio transceiver for connecting wirelessly
What do transmission media do
Carry data signals from one computer to another
What are the different types of transmission media (2)
Twisted copper wire
Fibre-optic cable
What are the properties of twisted copper wire (3)
Cheap
Up to 1 GB per second transmission speed
Reliable up to 100 metres
What are the properties of fibre-optic cable (3)
Expensive
Over 40 TB per second transmission speed
Reliable over 2km
What are the advantages of wired connections (2)
Reliable
Not usually subject to interference
What are the disadvantages of wired connection
Limited mobility
What are the advantages of wireless connections
Can connect to a network as long as it’s in range of the wireless access point
What are the disadvantages of wireless connections
Subject to magnetic interference
Limited in range
Can be blocked by walls
What are the types of network connection devices (NICs) (4)
Hubs
Switches
Wireless access points
Routers
What is a hub
A small device that allows wired devices to connect to a network
What are the disadvantages of a hub
It has no knowledge of devices connected so all traffic is transmitted to all connected computers which affects network performance
Why are switches better than hubs
A switch records which computers are connected so it only sends traffic where it needs to go which improves network performance
How does a wireless access point (WAP) work
It uses a radio transceiver to allow wireless connections to a network
It then sends wireless traffic to the main wired network
What is a router used for
Sending data signals across the internet
How do routers work
They collect knowledge of available routes to transmit data then determine the most suitable route
What do routers in homes include (3)
A hub
A WAP
Sometimes a modem
What does a modem do
Allows the user to connect to the internet
What is the internet
The network infrastructure of a worldwide collection of computer networks
What is the purpose of the internet
To enable communication on an international scale
What model does the internet predominantly use
Client-server model
How does the internet use to client-server model (3)
Web servers - store and maintain web content
Mail servers - handle web-based email
Media servers - allow clients to stream music and videos
What is hosting
The storing of files and data on a web server
What is the web server referred to in hosting
The host
What is the URL
Uniform resource locator - includes the host name for a website
What does the host consist of
Three hierarchical levels which work in reverse order of the name
Examples of the top level root of a URL (5)
.com .uk .net .gov .edu
What does the second level of a URL do
Denotes the type of organisation
Examples of the second level of a URL (4)
.co
.org
.sch
.ac
What does the third level of a URL do
Shows the organisation name
Examples of the third level (4)
bbc
ocr
microsoft
apple
What does DNS stand for
Domain name server
What is the format of a network address
Four sets of three digits
Why are domain names used
It is difficult for users to remember network addresses
What happens when a user enters a URL
A DNS (domain name server) takes the domain name and looks up its equivalent network address The user's request is then forwarded to the server that resides at that network address
What is The Cloud
A generic term for remotely accessed storage
How is The Cloud accessed
Through the internet
Where is data on The Cloud stored
On a server in a random location connected to the internet
What are the advantages to using The Cloud (3)
The ability to access files from any location or any device
Access can be granted to other users that can access your data
The need to make backups is reduced as cloud storages back up your data automatically
What are the disadvantages of using The Cloud (3)
There is no guarantee someone else is not accessing your data
There is no guarantee your data is being backed up
Access to data is only possible with an internet connection
How has the term ‘the cloud’ been turned in recent years
It is also a term for internet-based software facilities
What are the characteristics of internet-based software facilities (‘the cloud’) (2)
They offer limited versions of popular software
Ideal for low-powered devices or users that spend a lot of time travelling
What is a virtual network
A network of geographically unrelated computers connected together via the internet
How do virtual networks form their connections
Through the internet
What do virtual networks allow (2)
File sharing
Communication
Why do some organisations use virtual networks
To enable users to work from home as if they were in their workplace
What is network performance
Response time - how fast a message can be sent or how quickly a document can be retrieved
What are the factors that affect network performance (5)
Number of devices on a network Bandwidth of the transmission medium The type of network traffic Network latency Number of transmission errors
What is bandwidth
A measure of the amount of data that the medium can transfer over a given period of time
What is the bandwidth of twisted copper wire
1 gigabit (Gb) per second
What is the bandwidth of fibre-optic cable
Over 40 terabits (Tb) per second
What is the bandwidth of home Wi-Fi
54 megabits (Mb) per second
What is the bandwidth of business Wi-Fi
1 gigabit (Gb) per second
What happens to the bandwidth when a device joins a network
It gets divided between them equally, depending on the traffic being streamed
What is the network latency
A measure of how long it takes a message to travel from one device to another
What factors affect the network latency (2)
Number of devices on the network
Type of connection device
Why do hub-based networks experience more latency than switch-based
Hubs broadcast all messages to all devices whereas switches broadcast messages only to the intended recipient
What is fibre-optic generally used for
Allowing high data transmission between buildings
What is TCW (twisted copper wire) generally used for
Runs from switches within buildings to individual devices
What is Wi-Fi generally used for
Allowing guest devices to connect to the network
What is a collision
When two devices on a network try to communicate simultaneously along the same communication channel
When do more collisions occur
When there are more devices on a network
